I have a Davis VP2 and I also have a stream running through the middle of my
garden. Does anyone here have any experience with water level sensors?

Can any of them be tied into the Davis console? I'm not too bothered about
that really so long as I can get the data out of the sensor (wirelessly) in
real time I can log it to same database as my weather data.

It would be really nice to plot some graphs of rainfall against water level
and possibly programmatically predict when flooding is likely.


--
Brian Wakem
Lower Bourne, Farnham, Surrey
http://www.brianwakem.co.uk/weather

Freddie wrote:

Brian Wakem Wrote in message:
I have a Davis VP2 and I also have a stream running through the middle of
my garden.

It would be really nice to plot some graphs of rainfall against water
level and possibly programmatically predict when flooding is likely.

I think that you would be hard pressed to find any meaningful
correlation. The stream flows through your garden - so it has
come from somewhere else. You may get a better correlation with
rainfall data from the area of the source and course of the
stream.



The upstream catchment area is quite small and near, the source being about
1 mile away. It is spring fed so I would need to factor in rainfall over
some sort of moving average period and add on today's rain to get an
estimate of flow but I think it should be doable.


--
Brian Wakem
Lower Bourne, Farnham, Surrey
http://www.brianwakem.co.uk/weather

Well there's three parts to this question (other than interpretation, which
Freddie has started to address). Can you:

1. find a suitable water level sensor?
2. interface it to a VP2?
3. configure the logger/software to log the data?

As to [1] then I imagine the answer must be yes, though offhand I don't know
of any parts that are directly compatible. Don't expect the sensor
necessarily to be cheap though.

If you can arrange for the output of the sensor to be on a 0-3V scale (most
likely via some simple intermediate circuit that converts the native output
of the sensor to 0-3V) then yes it can be interfaced to certain inputs on a
VP2 - the UV sensor is the one most likely to be free. but there are other
options.

For [3], well, on a standard VP2 console/logger setup, the logged value
would be on the scale used by whichever sensor input you were using, eg for
UV it would be on a 0-16 UVI scale (IIRC). If however you were to use an
Envoy8X console to receive from your VP2 transmitter and log to the 8X's
WDTU software then that gives you full control over the scaling etc of the
new sensor reading and you could set the unit up to read in eg cm (or
whichever other units you preferred).

In summary, it's all perfectly feasible in principle but it would require
some development. And the final readings would make much more immediate
sense if an Envoy8X console were used.

Brian Wakem Wrote in message:
I have a Davis VP2 and I also have a stream running through the middle of my
garden.

It would be really nice to plot some graphs of rainfall against water level
and possibly programmatically predict when flooding is likely.

I think that you would be hard pressed to find any meaningful
correlation. The stream flows through your garden - so it has
come from somewhere else. You may get a better correlation with
rainfall data from the area of the source and course of the
stream.

--
Freddie
Pontesbury
Shropshire
102m AMSL
http://www.hosiene.co.uk/weather/
http://twitter.com/PontesburyWx for hourly reports


----Android NewsGroup Reader----
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On Saturday, September 26, 2015 at 7:46:54 AM UTC+1, Freddie wrote:
Brian Wakem Wrote in message:
I have a Davis VP2 and I also have a stream running through the middle of my
garden.

It would be really nice to plot some graphs of rainfall against water level
and possibly programmatically predict when flooding is likely.

I think that you would be hard pressed to find any meaningful
correlation. The stream flows through your garden - so it has
come from somewhere else. You may get a better correlation with
rainfall data from the area of the source and course of the
stream.


--
Freddie
Pontesbury
Shropshire
102m AMSL
http://www.hosiene.co.uk/weather/
http://twitter.com/PontesburyWx for hourly reports


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

There is an interesting correlation between the stream in my garden and river flooding at Newlyn. The source of both are the Penwith moors 4 or 5 miles away, then they run down parallel in NW-SE aligned valleys. Runoff is rapid.

On 3 occasions (since 2007) the stream has just covered a sewage pipe which crosses it, and on each occasion there has been flooding at Newlyn. There have been no other cases of river flooding at Newlyn during the same period.

The EA should attach a warning sensor to the the top of the pipe!

Graham
Penzance 6.3C min last night, coldest since the Spring.

Brian Wakem Wrote in message:
Freddie wrote:

Brian Wakem Wrote in message:
I have a Davis VP2 and I also have a stream running through the middle of
my garden.

It would be really nice to plot some graphs of rainfall against water
level and possibly programmatically predict when flooding is likely.

I think that you would be hard pressed to find any meaningful
correlation. The stream flows through your garden - so it has
come from somewhere else. You may get a better correlation with
rainfall data from the area of the source and course of the
stream.



The upstream catchment area is quite small and near, the source being about
1 mile away. It is spring fed so I would need to factor in rainfall over
some sort of moving average period and add on today's rain to get an
estimate of flow but I think it should be doable.

Looking at your location, I guess you are near to chalk-based
bedrock - so your catchment definition could be complex. I don't
envy you trying to to do this...

--
Freddie
Pontesbury
Shropshire
102m AMSL
http://www.hosiene.co.uk/weather/
http://twitter.com/PontesburyWx for hourly reports


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

Brian Wakem Wrote in message:
Freddie wrote:

Brian Wakem Wrote in message:
I have a Davis VP2 and I also have a stream running through the middle of
my garden.

It would be really nice to plot some graphs of rainfall against water
level and possibly programmatically predict when flooding is likely.

I think that you would be hard pressed to find any meaningful
correlation. The stream flows through your garden - so it has
come from somewhere else. You may get a better correlation with
rainfall data from the area of the source and course of the
stream.



The upstream catchment area is quite small and near, the source being about
1 mile away. It is spring fed so I would need to factor in rainfall over
some sort of moving average period and add on today's rain to get an
estimate of flow but I think it should be doable.

Looking at your location, I guess you are near to chalk-based
bedrock - so your catchment definition could be complex. I don't
envy you trying to to do this...

--
Freddie
Pontesbury
Shropshire
102m AMSL
http://www.hosiene.co.uk/weather/
http://twitter.com/PontesburyWx for hourly reports


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

Freddie wrote:

Brian Wakem Wrote in message:
Freddie wrote:

Brian Wakem Wrote in message:
I have a Davis VP2 and I also have a stream running through the middle
of my garden.

It would be really nice to plot some graphs of rainfall against water
level and possibly programmatically predict when flooding is likely.

I think that you would be hard pressed to find any meaningful
correlation. The stream flows through your garden - so it has
come from somewhere else. You may get a better correlation with
rainfall data from the area of the source and course of the
stream.



The upstream catchment area is quite small and near, the source being
about
1 mile away. It is spring fed so I would need to factor in rainfall over
some sort of moving average period and add on today's rain to get an
estimate of flow but I think it should be doable.

Looking at your location, I guess you are near to chalk-based
bedrock - so your catchment definition could be complex. I don't
envy you trying to to do this...




'Gault Clay' according to this
http://www.bourneconservation.org.uk/geology.htm


--
Brian Wakem
Lower Bourne, Farnham, Surrey
http://www.brianwakem.co.uk/weather

JohnD wrote:

Well there's three parts to this question (other than interpretation,
which Freddie has started to address). Can you:

1. find a suitable water level sensor?
2. interface it to a VP2?
3. configure the logger/software to log the data?

As to [1] then I imagine the answer must be yes, though offhand I don't
know of any parts that are directly compatible. Don't expect the sensor
necessarily to be cheap though.

If you can arrange for the output of the sensor to be on a 0-3V scale
(most likely via some simple intermediate circuit that converts the native
output of the sensor to 0-3V) then yes it can be interfaced to certain
inputs on a VP2 - the UV sensor is the one most likely to be free. but
there are other options.

For [3], well, on a standard VP2 console/logger setup, the logged value
would be on the scale used by whichever sensor input you were using, eg
for UV it would be on a 0-16 UVI scale (IIRC). If however you were to use
an Envoy8X console to receive from your VP2 transmitter and log to the
8X's WDTU software then that gives you full control over the scaling etc
of the new sensor reading and you could set the unit up to read in eg cm
(or whichever other units you preferred).

In summary, it's all perfectly feasible in principle but it would require
some development. And the final readings would make much more immediate
sense if an Envoy8X console were used.


The UV sensor is using the UV input :-)

Perhaps I could use the wind input since that is not in use? The anemometer
uses a separate wireless sender as it's on a pole on the roof.

It doesn't really matter to me what units or scale it produces since I have
my own script running between the log files 'WeatherDisplay' produces and my
database so I can fudge it as necessary.

Finding a suitable sensor is going to be the hard part I think.


--
Brian Wakem
Lower Bourne, Farnham, Surrey
http://www.brianwakem.co.uk/weather

"Brian Wakem" wrote in message ...

The UV sensor is using the UV input :-)

Perhaps I could use the wind input since that is not in use? The anemometer
uses a separate wireless sender as it's on a pole on the roof.

It doesn't really matter to me what units or scale it produces since I have
my own script running between the log files 'WeatherDisplay' produces and my
database so I can fudge it as necessary.

Finding a suitable sensor is going to be the hard part I think.
================================================

OK so both UV and (presumably) solar too are already in use? There's no
other input on a standard SIM that you can use. (Wind is not a standard 0-3V
input) Options a

1. Buy a 6345 multi-sensor transmitter and use one of the soil moisture
inputs on that;

2. (Assuming your anemometer transmitter is relatively inaccessible Buy
another standard transmitter - 6372 Temp-only would be the cheapest option
and receive data on either an Envoy8X console or a MeteoStick receiver.

I don't think that finding a level sensor will be hard - there's plenty of
different types around. One apparently cost-effective type (never seen one,
but from a quick Google search) that I might be tempted to look at further
is:

http://milonetech.com/products/standard-etape-assembly

Where you will need to do some development is adapting this to give a 0-3V
output. May not be very difficult for a simple resistive output like this
sensor appears to have, but will still need an element of electronics input.

John Dann
www.weatherstations.co.uk